Methine dyestuffs



l atented June 13, 1950 Ilford, England, assignors to llford l imited Ilford, England, a British company :No Drawing. Application Marchli), 1947, Serial I No. 735,819. In Great Britain April 1, 1946 Claim-sf (Cl. 260-240) [This invention relates to the production or or; ganiccompounds and to the, optical sensitisation" oifsilyer halide photographic emulsions. In our application Serial No. 687,939, ow Pat-I ent No. 2,493,071, we have described processes whereby organic compounds may be obtained having the general formula:

(i. e. compound (1) in.1Figure,,4.- ,ofzthefor-mulae drawings accompanying that application) where R1 .is a hydrocarbon group ,and B4 is an alkyl group. By the use of an aralkylating agent instead of an alkylating agent'in the process of that application compounds may be obtained-in which an aralkyl group. i It has now been discovered that .such compounds react with compounds .containing reactive methylene groups or reactive groups-to form organic compounds many. of which.are.sen-. sitising- :dyes for silver. halide. .lphotographic emulsions.

According to the present invention, therefore, useful organic compounds ,are obtained by condensing a compound of the general Formula I:

whereRi is a hydrocarbon group and is alkyl or aralkyl; with a heterocyclio nitrogen *com: pound containing areactiv'e'methylene group, in the presence of a basic condensing agent. The reactive methylene group may be intracyclic or extr'acyclic. 1 *In particular, according to this invention,-- a

" compound of general Formula I is condensed with aeompound of general Formul II: I 1 H 'alkyl or aralkyl group, X is an acid radicle arid D1 is the residue of a five-membered or six-mem bered heterocyclic ring, or with a compound of general Formula III:

r t-o -bit,

where' Dz is the residue of a general Formula III; which yr, heterocyclic nitrogen ketd-methyleifie ring and R5 is a hydroge'n atoiii or a hydrocarbon group. p j' l Where the second reagent is a commander 7 corresponds t e more specific Formula:

5 where1 Y is' an. oxygen, atom or a sulphuratoiiif the, product may be convertedto an'alkyl 'oria'r I allgy altand this'reacted with a compound a 'j' ta'iiiin'g a reactive m'ethylenebr NH gro' series of reactions may" 'beefiect'ed' in'an' ar a gous manner to that described in U. S. Patent'Ndi' The groups R1 and R5 may be any hydrocarbon groups, e. g. alkyl, aralkyl or aryl and, as stated above, the groups R2, R3 and R4 may'also be alkyl or aralkyl. Alkyl groups may be methyl, ethyl, propyl, butyl or higher alkyl, and aralkyl groups may be, for example, benzyl-and naphthylmethyl. In addition groups R1 and; R5 maybe arylner-i g. phenyl or naphthyl. ,Theresiduo Di, maybe, ,for example, theresidlii oiyany; oi. the types of heterocyclic nuclei ppm monly employed i photographic sensit ns d a thiazo e vcxazc s s e a o es and -i. po y y c omologues such. a ho eo that zene, naphthalene, acenaphthene and anthracene series; pyridine and its polycyclic homologues such as quinolineand a and; p naphthaquinolines; lepidines; indolenines; diazines such as pyrimidines and quinazolines"; diaaoles (e. g. thio-BB-diazole); oxazolines, thiazolines and selenazolines. The polycyclic compounds of these'series may be substituted in the carbocyclic ringsby one or more groups such as alkyl;;aryl, amino, hydroxy, alkoxy and methylene-dioxy groups or by halogen atoms. I J

The compounds of general Formula Kidney be, for example, rhodanic acid (2 thio-4-kto' tetrahydrothiazole)oxarhodanic acid (2-thio-4- ketotetrahydro-oxazole), and the N-hydroc arbon fderivatives of such compounds;' 'foxindoles, pyr'a'zole fi-ones, hyd'antoin, thiohydantoin i// dantoin and D-thi -hydantoin. I ,ic examp" The dyes produced using a reagent of general Formula II have the probable formula:

e s illu t ate the 1.

Example 1 Equimolecular quantities of fi-cyano-fi-carbethoxyketene di-methylmercaptal, petoluquinale dine and methyl-p-toluene sulphonate were fused together for 3 hours at 100 C. The product was dissolved in pyridine and the solution boiled gently under reflux for minutes. Methyl mercaptan was evolved. The reaction mixture was then poured into water and the aqueous mixture extracted with diethyl ether. The ether solution was washed with water and dried over anhydrous sodium sulphate. The ether was then evaporated leaving an oil which hardened on i iviati t r leum e her ld n h solid dye. On recrystallisation from a mixture of benzene and petroleum ether it was obtained as crystals melting at 114 C. The dye had the probable formula:

- The procedure of Example 1 was followed-using l-methyl benzthiazole instead of p-toluquinaldine. Onpouring the reaction mixture into water the dye precipitated as an oilwhich hardened on standing into shining brown crystals. The recrystallised product'melted at 158 C. and had theprobable formula:

This dyestufi, when incorporated in a gelatino silver chloride emulsion, imparts a-band of sensi-. tivity extending to 5500 A. with a maximum at 5100 A. Included in a gelatino-silver iodobromide emulsion the maximum sensitivity is at'5300 A.

Example 3 4 zene and concentrating and diluting the benzene extract with petroleum ether, whereupon the required dye separated out. It had a melting point of 155 C. and the probable formula:

This dyestuff, included in a gelatino silver chloride emulsion, imparted a band of sensitivity extending to 5000 A. with a maximum at 4700 A.

Example 4 The [procedure of Example 1 was followed using l-methyl benzoxazole instead of the ptoluquinaldine. Refluxing was continued for minutes and the reaction mixture was poured into aqueous alcohol instead of plain water. The dye precipitated and after recrystallisation from a mixture of benzene al d petroleum ether was obtained as crystal melting at 126 C. It had the probable formula:

0 SCH! CN \IQ=OH o o 0 01H:

This dyestuff, included in a gelatino silver chloride emulsion, imparted a band of sensitivity extending to 4800 A. with a maximum at 4500 A.

Example 5 The procedure of Example 1 was followed using l-methyl fl-naphthathiazole instead of the p-.-toluquinaldine. The reaction mixture was poured into aqueous ethyl alcohol whereupon the dye precipitated. The dye was purified by recrystal: lisation from methyl alcohol. It had a melting point of 211 C. and the probable structure:

. This dyestuff, when included in a gelatino silver iodobromide emulsion, imparts a band of sensitivity with a maximum at 5450 A.

Example 6 This dyestuff, when included in a gelatino silver chloride emulsion, imparts a band of sensitivlty extending to -5800 'A' witha-maximum at 5100 'Af Included in a gelatino iodobromide emulsion the sensitivity extends to 5 00 a; v 1

, Example 7 Equimolecular quantities of p-cyanmp-c'arbeth oxyketene dimethylmercaptal; me'thyl thiazoline and methyl 'p-toluene sulphonate were fusedtogether for 2 hours at 100 C. The product was dissolved in pyridine and the solution boiled gently under reflux for 20 minutes. The reaction mixture was then poured into aqueous ethyl a1- cohol. On dilution with water, the dye precipitated. I It was separated and-recrystallised from methyl alcohol: solution yieldingthe product ascrystals melting at 129 C. It had the probable formula:

This dyestufl, when includedin a gelatino silvexchloride emulsion, imparts. a band of sensitivity extending to 450ml.v

Exampleli' v Equimolecular quantities offl-cyano-pcarbethoxyketene dimethylmercaptal, l-methyl benzthiazole and ethyl p-toluene sulphonate were fused together for 24 hours at 100 C. The mixture was then boiled gently under reflux in pyridine for 15 minutes. The dye precipitated and.

after filtration and recrystallisation from methyl alcohol, was obtained'as mauve crystals melting at 146 C. and giving a bright yellow solution in alcohol. The dye had the probable formula:

sent CN O=CH =.C:..

' The above dyestufi, when included in agelatino silver iodobromide emulsion, imparted a band of sensitivity with a maximum at 5300 A.

Exampleil 1;

CLUB- on, I =1 The above dyestufi, when included in a gelatino silver iodobromide emulsion, imparts a band of sensitivity extending to 5600 A. with a maximum at about 5300 A.

4700 A. with a maximum of.

" Example 10 i Equimolecular quantities of p-cyano-p-carbetlioxyketene diethylmercaptal, and l-methyl benzthiazole p-hydroxy ethiodide were boiled gently under reflux with ethyl alcohol and an equimolecular quantity of triethylamine. The boiling was continued for "5 minutes and then the reaction mixture was cooled and diluted with a little water. The dye precipitated and was purified "by extraction withanhydrous diethyl ether followed by recrystallisation from ethyl alcohol." It wasthus obtained as red rhombs with a blue reflex, meltingatl52 C. It had the probable formula;

The above dyestuif, when included in a gelatino silver iodobromide emulsion, imparts a sensitivityextending, to. 5500 A. l

Example 11 Equimolecular quantities of p-cyano-B-cQ-bth I oxyketene dibenzylmercaptal and l-methyl benzthiazole methiodide were boiled under reflux in ethyl alcohol solution for 15 minutes. The solution was cooled and diluted with a little water,

whereupon the dye precipitated. On recrystall'i sation from ethyl alcohol it was obtained as' bright red crystals, melting at C. It had the" probable formula:

/ 4 sum-cum C=CH- ,The abovedyestuff, when included in gelatino. silver iodobromide-emulsion, imparts aband of;

sensitivity extending to 5500 A.

The dyes of this invention are of especialvaluev not only as normal photographic sensitising dyes but in the production of variable contrast emulsions according to the method of U. S. Patent No. 2,280,300.

What we claim is:

1. Process for the production oidyestuflswhich comprises condensing a compound of'the general formula:

ON SR Rio 0 o 1 where'nr is a hydrocarbon group and R4 is selected from the class consisting of alkyl and aralkyl groups with a heterocyclic nitrogen com-' pound containing a reactive methylene group, the said condensation being effected in the presence of a basic condensing agent. i

2. Process for the production of dyestuiis which comprises condensing where" [R1 is a 'hydrocarbon group-and Riv- 8588 lected -irom"*the- "class consisting- 01 alkyl and band- .Of 1

a compound of thegen'eral I. pound of the general 4 R j whereRg is selected from the class consisting oi alkyl and hy roxy lk l gro p o s lect d FQm the clas consisting of 'thehydrogen atom, and lkr an aral y g o ps a c radish. no s Sel ct r m. nou ht and o e: an D is the esid Of a fi -membere or sixmembeIsd, heterocyclic ringl the said condensation. being effected in the presence of a basic condensing agent.

3. Process for the production of dyestuffs which comprises condensing a compound of the general formula:

B'XQ SR! whereRi is a hydrocarbon group and Rl'is sc-v lected from the class consisting of alkyl and aralkyl groups with a compound of the general .5

o mooo SR4 where'Ri is a lower alkyl group and R; is se;

lected from the class consisting of alkyl and aralkyl groups with a compound of the general wesr ts s sele ted tram the slassmnsisties of a isylandih xosie s roans Ba sssls tsd rem the'class consisting of'the hydrogen atom and; alkyl and aralkyl groups, X is an acid radicle, n is selected from nought and one, and D1 is the residue of a five-membered or six-membered heterocyclic ring, the said condensation being effected in the presence of a basic condensing agent.

omp ises c nd nsin a ssmmu t the g neral rmu a: I

i Q Q $.34 these-Rosa ydroca on o p some alkyl group with a compound of the general? formula:

im nouns. Br a-s lecte trees: 1;

8-:- h irthah d ogen atom -;a-ud.=' alls lan m k stom s, X is an aci 1110133? n. is ed item nou ht and a d D1 visitlm residue of a flve-membered or six-membered heterocyclic ring, the saideondensation being effected th 'presens o bas c conde s misssn 6-.. Pro ss for h produ io o d e fi wb ch omp ses c ndenses a c mp f he en ral: ormula-'1. I 1 r where 31 is a hardrocarbon group and Roisv lower alkyl group with a compoundvoi the gem emlimmuh:

where R: is. selected from the class consisting of alkyl and hydroxyalkyl groups, X is an acid radicle, n is selected from nought and one, and D1 is the residue of a five-membered or six-membered heterpcyclicv ring, the said condensation beingefiected in the presence of a. basic condom ingagent. Y 1,

7. Process for the production of dyestufis which comprises condensing a compound of the general formula:

where R1 is a lower alk l group andRl is se.-. lected from the class consisting or allgyl and? arallrylgroups witha compound or the general formula:

rir-oo-on.

where D2 is the residue ofa heterocyclic nitrogen ketomethylene ring, and R5 is selected from the class consisting of the hydrogen atom and hydrocarbon groups, the said condensation being ffec ed n e presenc o a as c ondens n ge I h or henmduct on f dre t fiswhieh comprises condensing a compound of the general formula:

ON R1 R QQ SBA er 3 nd Rw e lower a ky r up ompou df e gener i mu r- '1 N-c O('JH:

, with a! v where Dads theresiduo ofxa heterocyclic nitrogen, ketomethylene ring; and R5 is selectedfromthe. class consisting of the hydrogen atom and hydrocarbon groups, the said condensation being efcomprises condensing a compound of the general formula:

' QN- 8B4 where R1 and R4 are lower alkyl groups with a compound of the general formula:

IiI-C o-H,

where D2 is the residue of a heterocyclic nitrogen ketomethylene ring, and R5 is a lower alkyl group, the said condensation being effected in the presence of a basic condensing agent.

10. A dyestufi of the formula:

where R1 is a hydrocarbon group, R2 is selected from the class consisting of alkyl and hydroxyalkyl groups, R4 is selected from the class consisting of alkyl and aralkyl groups, n is selected from nought and one, and D1 is the residue of a five-membered or six-membered heterocyclic ring.

11. A dyestuff of the formula:

r D2-| SR4 ON 1 I-0o-3JHo=c 5 \COOR1 where R1 is a hydrocarbon group, R4 is selected from the class consisting of alkyl and aralkyl 10 groups, R5 is selected from the class consisting of the hydrogen atom and hydrocarbon groups, and D2 is the residue of a heterocyclic nitrogen keto-methylene ring.

JOHN DAVID KENDALL. HARRY DEREK EDWARDS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS OTHER REFERENCES Chemical Abstracts 16;310'1 (Abstract of Brit. Med. Journal, 1922, I 514-515).

Chemical Abstracts 19;530 (Abstract of Proc. Roy 300.. London, 963, 317-333, 1924). 

1. PROCESS FOR THE PRODUCTION OF DYESTUFFS WHICH COMPRISES CONDENSING A COMPOUND OF THE GENERAL FORMULA: 